1. Field of the Invention
The present invention provides novel intermediates and their use in the preparation of certain histamine H.sub.2 -antagonists which are useful in the treatment of peptic ulcers and other conditions caused or exacerbated by gastric acidity.
2. Disclosure Statement
Our colleagues A. A. Algieri and R. R. Crenshaw disclose histamine H.sub.2 -receptor antagonists in U.S. Pat. Nos. 4,390,701 issued June 28, 1983, 4,395,553 issued July 26, 1983, 4,522,943 issued June 11, 1985 and 4,526,973 issued July 2, 1985 which are substantially the same as those described by the present invention.
U.S. Pat. No. 4,521,625 issued June 4, 1985 to T. H. Brown and R. C. Young discloses intermediates of the formula ##STR3## wherein R.sup.1 is hydrogen or a C.sub.1-6 alkyl group and X is hydroxy or a group displaceable by hydroxy or the equivalent thereof which are used in a process for the preparation of compounds which are substantially the same as those described in the above-mentioned U.S. patents.
United Kingdom patent application GB No. 2,023,133 published Dec. 28, 1979 discloses inter alia intermediates of the formula ##STR4## in which W represents the group --CHO or --(CH.sub.2).sub.p CONR.sub.1 R.sub.2 and Q, n, X, m, R.sub.3, R.sub.4, R.sub.5, R.sub.1 and R.sub.2 correspond to a large number of substituents.
The novel intermediates provided in the present invention are useful in an improved process for the preparation of histamine H.sub.2 -antagonists described herein.